Should fans blow at my lights or suck air out

[john_waggs]

I am mounting 4-6 T5 lights in an enclosed wooded canopy with only an opening in the back. I want to mount two Ice Cap thermostatic fans at the rear. I'm getting conflicting information...some say to blow both fans towards the lights, others say to have one fan blow in and the other to blow out.
Hopefully I can get some answers here.

 

[john,jr]

Originally Posted by john_waggs
http:///forum/post/2570422
I am mounting 4-6 T5 lights in an enclosed wooded canopy with only an opening in the back. I want to mount two Ice Cap thermostatic fans at the rear. I'm getting conflicting information...some say to blow both fans towards the lights, others say to have one fan blow in and the other to blow out.
Hopefully I can get some answers here.
I am no expert but I would have 1 in 1 out. That way you will have more circulation and cooler air which will cool the lights more.

 

[bill109]

from what i know.. u would wnat them both out.. becasue the lights wont be working as well if they are running at a cooler temp. but if you are pointing both fans out.. it will suck out all the hot air. from what i have been told t-5's work best at certain temps..?

 

[bill109]

if you can run one across the top of the fixture. and the other pulling out this way there isnt a direct breeze from the fan on the blulbs

 

[mckaax]

I remember hearing that is was better for the fans to have then blowing in. Something to do with moisture in the air.

 

[reefkprz]

You should have them sucking the air out, blowing inward adds the heat from the fans motor to the canopy, sucking out vents the fans heat as well as drawing cooler air in the other side. also you tend to get dust build up quicker in the path of the air if the fans are pointing in.

 

[fish4ever]

Originally Posted by reefkprZ
http:///forum/post/2570647
You should have them sucking the air out, blowing inward adds the heat from the fans motor to the canopy, sucking out vents the fans heat as well as drawing cooler air in the other side. also you tend to get dust build up quicker in the path of the air if the fans are pointing in.
I agree with reef

 

[florida joe]

There are to many variables to give a stock answer IMO like the ambient temp of your house how high you lights are above the water how fast evaporation takes place. Try different combinations of air flow in and out of your canopy. Let the water temp stabilize record them and go with what works best for your situation

 

[bang guy]

It depends on what you want to cool.
Point the fans at the bulbs to cool the bulbs.
Point the fans at the water to cool the water.
Point one in and one out to cool the air in the canopy (but why?)

 

[reefraff]

Best way I've found is running both fans pointed in from the back so they blow across the ends of the lamps at the endcaps.

 

[john_waggs]

Thanks for all the info.

 

[ifirefight]

It really depends on your set-up. If you have a canopy,then I recommend both blowing IN. With that being said,you MUST have an opening sufficient to keep up with the CFMs produced by the fans. This is called positive pressure ventalation...we use this in firefighting. If you blow air in...it HAS to escape some how...so ,the opening should be large enough to VENT all the hot air out. If you draw (s u c k ) air out, it will bring all the nasty SW air across the fans ..thus shortening there life span. Also,most fans are designed to BLOW air not draw it out. More efficient to use positive pressure...IMO.

 

[bigleman]

Originally Posted by ifirefight
http:///forum/post/2578977
It really depends on your set-up. If you have a canopy,then I recommend both blowing IN. With that being said,you MUST have an opening sufficient to keep up with the CFMs produced by the fans. This is called positive pressure ventalation...we use this in firefighting. If you blow air in...it HAS to escape some how...so ,the opening should be large enough to VENT all the hot air out. If you draw (s u c k ) air out, it will bring all the nasty SW air across the fans ..thus shortening there life span. Also,most fans are designed to BLOW air not draw it out. More efficient to use positive pressure...IMO.

+1
I have a 250w MH, so i dont know if that changes things.
but I have my fans low and on the sides of my canopy blowing in. That way it pulls cool air in and pushes the hot air out the back instead of pulling the hot air across the top of the water. It also gets a little water movement on the surface.